Apparatus for applying viscous coating compositions to wire



July 3, 1951 H. w. sTuRGls ETAL 2,553,993

APPARATUS FOR APPLYING VISCOUS comme coMPosIToNs To WIRE Filed Feb. 15, 1949 F l G. 2

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slanted .my a, 1951 APPARATUS FOR APPLYING VISCOUS COATING COMPOSITINS T WIRE Howard W. Sturgis and Emil ll. Olson, Muskegon. Mieli., assignors to Anaconda Wire and Cable Company, a corporation of Delaware l Application February 15, 1949, Serial No. 76,442

3 Claims. (Cl. ill-32) This invention relates to apparatus for applying viscous coating compositions to wire, and is particularly concerned with the provision of an improved apparatus for applying viscous gelable lacquers to copper wire in the manufacture of in'- sulated magnet wire.

The new apparatus comprises a vessel for containing the coating composition, and a rotatable f wheel having a cylindrical face partially immersed in the composition. The cylindrical face of said wheel is formed with a peripheral groove for receiving a wire and guiding it down into and up again out of the coating composition. A wiper element having a cylindrically curved face of approximately the same radius of curvature as vthe rotatable wheel bears against the cylindrical face of said wheel about at the point where the wire emerges from the coating composition, the wiper element being restrained from rotation about the The wiper element is advantageously in the form of a nonrotatable wheel fastened to an arm which in turn is pivotally mounted on the frame that carries the rotatable wheel. vSpring means then are provided for urging the wiper supporting arm on its pivotal mounting toward the rotatable wheel, thereby to bring the curved face of the wiper element intojengagement with the cylindrical face of the rotatable wheel.

A preferred embodiment of the invention is shown in the accompanying drawings, in which Pig. 1 is a perspective, partly in section. oi' the new apparatus; and

Fig. 2 is a section taken substantially along the line 2-2 of Fig. l.

'I'he apparatus shown in the drawings comprises a vessel i containing a body of gelable lacquer C. The veel l is suspended in a jacket 1 .containing a body of water l heated by a thermostatically controlled heater l to a temperature above the gelation temperature oi' the coating composition, whereby the coating composition is kept at the optimum temperature for application to a wire.

Suspended in the vessel I is an applicator Il which serves to guide a wire into and out of the body of gelable lacquer l, and to control the thickness of the coating of such lacquer that is formed on the wire. The applicator comprises a transverse frame member il fastened to a bar I2 by which the applicator is suspended in the vessel I. g A vertical frame member l2 is rigidly fastened to the transverse frame member Ii at one end thereof. A wheel Il is rotatably mounted on a shaft il secured to the vertical frame member 2 l2 near its lower end, and is held in place by la collar II. The wheel i4 is formed with a cylindrical face il in which a peripheral groove Il is cut.

An arm l! is pivotally mounted, by means of a pivotpin 2l and retaining collar 2|, on the transverse frame member I I. The arm I9 carries a wiper element 22 at its lower end. The wiper element is in the form of a wheel non-rotatably mounted on a'pin 22 rigidly attached to the arm i9. The wheel is held in place by a collar 2l. The pin 2l is shown as being rectangular in cross section. passing through a corresponding rectangular hole in the wiper 22. to prevent rotation of the wiper about the center of curvature of its face 25; but it is evident that other mechanical expediente than the rectangular pin 22 may be used to restrain the wiper from rotation.

The wiper element 22, like the rotatable wheel i4, is formed with a cylindrical face 25, and is mounted in such position that its face 25 may be swung by movement of the arm Il against the face Il of the rotatable wheel about at the surface level oi the body of lacquer 6. Pins 26 and 2l are fastened to the vertical frame member Il and to the arm Il, respectively, and a tension spring 28 engaging these pins urges the cylindrical face of the wiper element into contact with the cylindrical face Il of the rotatable wheel Il.

Operation of the apparatus is as follows: A wire 22 to be coated is looped around the rotatable wheel, engaging in the peripheral groove Il in the face thereof; and it is guided by the rotatable wheel down into the body of lacquer 6 and then up again out of the lacquer. -In consequence oi' thus having been immersed in the body of lacquer, the emerging wire 2l is provided with a coating of the lacquer. The thickness of the coating on the emerging wire is hunted by the action of the wiper element 22, which insures that the crosssectional area of the coating on the wire is substantially equal to the difference between the cross-sectional areas of the uncoated wire and of the peripheral groove Il. As best shown in Fig. 2, the groove is triangular in cross section and deep enough so that the wire does not project above the face Il of the. wheel Il. As the wire emerges i'rom the lacquer, and from the peripheral groove Il, the viscous lacquer ilows suili ciently, before it gels, t0 form a uniform cylindrical coating about the underlying wire.

It is important that the wiper element 22 be large enough so that the viscous lacquer cannot flow around it and so add to the` thickness di' the coating after the wire has emerged from the body of lacquer. This is most conveniently accomplished by making the wiper element 22 in the form of a wheel having substantially the same radius of curvature and the same width of face as the rotatable wheel. However, the wiper element need not be a wheel of exactly the same size as thel rotatable wheel. It may be in the form of a non-rotatable wheel having a diameter that ranges from about one-half up to three or four times the diameter of the rotatable wheel, and its face width may be any amount greater than that of the rotatable wheel. The face width of the rotatable wheel, and consequently the face width of the wiper element (measured in a direction. parallel to the axis ofthe wheel) should be at least three times as great as the maximum width of the groove i8, and preferably five times or more the maximum width of such groove, in

30 to 45 is ordinarily suiiicient for this purpose. 'I

It is important, however, that the wiper element be non-rotatable about the center of curvature of its face. It has been found that if the wiper out of the liquid coating composition, said wheel being freely rotatable whereby its speed of rotation is determined solely by the speed with which the wire is drawn through the coating composition, and a wiper element having a. cylindrically curved face of approximately the same radius of curvature as the rotatable wheel bearing against the cylindrical face of said wheelv aboutl at the point where the wire emerges from the coating composition, the wiper element being restrained from rotation about the center of curvature of its face, and the center of the wheel and the center of curvature of the face of the wiper element being substantially horizontally aligned.

. 2. Apparatus for applying a viscous liquid coating composition to a wire comprising a vessel for containing the composition, a rotatable wheel having a cylindrical face partially immersed in the composition, the cylindrical face of said wheel being formed with aV peripheral groove for receiving a wire and guiding it down into and substantially vertically up again out of the liquid coating composition, said wheel being freely rotatable whereby its speed of rotation is determined solely by the speed with which the wire is drawn through the coating composition, and a, wiper element in the .form of a non-rotatable wheel having a cylindrical face of approximately the same radius of curvature as the rotatable Wheel, the cylindrical face of the non-rotatable wheel bearing against the cylindrical face of the rotatable wheel about is in the form of a rotatable wheel, the coating formed on the wire is of irregular thickness; and sometimes is actually stripped from the wire immediately upon emergence of the wire from the body of lacquer.

It is not essential that the peripheralgroove il in the rotatable'wheel have the triangular cross section shown in the drawings. It may equally well be square, oval or of any other desired cross-sectional shape. However, a triangular groove is very easily formed to accurately control dimensions, and it is fully as satisfactory as other groove shapes.

'I'he copending application of Harry L. Saums Patent No. 2,547,047, issued April 3, 1951, describes and shows an applicator more or less similar to that described and claimed herein, but having two rotatable grooved wheels. The applicator of the present invention has been found to be more satisfactory than that of the Saums et al. application because it has been found difycoating composition to a wire comprising a vessel for containing the composition, a rotatable wheel having a cylindrical face partially immersed in the composition, the cylindrical face of said wheel being formed with a peripheral groove for receiving a wire and guiding it down into and up again,

at the point where the wire emerges from the coating composition.

3. Apparatus for applying a viscous liquid coating composition to a wire comprising a wheelsupporting-.frama awheel having a peripherally y grooved cylindrical face mounted for free rota- -tion on said frameja wiper-supporting arm pivotthe face of the wiper element being substantially horizontally aligned and spring means urging the Y wiper-supporting arm on its pivotal mounting et al., serial No. 749,804, filed May 22, 1947, now

able wheel.

toward the rotatable wheel, whereby to bring the cylindrical face of the wiper element into engagement with the cylindrical face of the rotat- HowARD w. s'rURGIs; mm. H. oLsoN. nnFEnENcEs crrEnr The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number' Name Date 1,387,606 Meyer Aug. 16, 1921 1,969,667 Kress Aug. 7, 1934 2,156,607 Schon May 2, 1939 2,197,622 Sendzimir Apr. 16, 1940 2,239,862 Bailey July 14, 1942 2,323,487 Rayburn July 6, 1943 2,350,742 Fordyce June 6, 1944 

